100 ACTA BOT. CROAT. 83 (2), 2024 Acta Bot. Croat. 83 (2), 100-106, 2024 CODEN: ABCRA 25 DOI 10.37427/botcro-2024-013 ISSN 0365-0588 eISSN 1847-8476 Does palynotaxonomy contribute to the systematics of the genus? The section Multicaulia of the genus Hedysarum (Fabaceae) example in Türkiye Burcu Yilmaz Çitak University of Selçuk, Faculty of Science, Department of Biology, 42130 Konya, Türkiye Abstract – The purpose of the current work was to assess the systematic and taxonomic significance of the pollen morphological characteristics of the Multicaulia section of Hedysarum species found throughout Türkiye using scanning electron microscopy (SEM) and light microscopy (LM) techniques. For this reason, seven different species currently classified in the Multicaulia section were collected from various localities. The pollen grains were nonaceto- lyzed, prepared and directly measured according to the Wodehouse method. Pollen grains were found to be subprolate in H. nitidum but prolate in others and the exine sculpturing pattern was determined to be microreticulate-perforate in six taxa while only H. varium subsp. syriacum had reticulate-perforate sculpture. The minimum exine thickness was measured at 0.96 μm in H. varium subsp. varium, while among the investigated species, H. nitidum had an exine measurement of 1.38 μm. In this study, multivariate analysis was used to investigate nine qualitative and quantitative features. Data cluster analysis revealed that the pollen characteristics were important in helping to distinguish the different species from one another. The results demonstrated that the genus Hedysarum of the section Multicaulia was divided into two major groups based on variations in pollen dimensions. The usefulness of certain pollen morpho- logical traits was assessed, and the congruency of the palynomorphological investigations was examined. The findings demonstrated the significance of pollen micromorphology in precisely identifying and categorizing the Multicaulia section. Keywords: Hedysarum, Leguminosae, palynology, taxonomy, sweet vetch, systematic Introduction It is a broadly acknowledged theory that the fields around the large Tethys Sea (which covered part of the present Mediterranean zone during the Tertiary) became a center of speciation for many plant families after the Alpine uplift and Oligocene climatic changes during the Pleistocene and Holocene. Only several legume tribes such as Hedysareae, Genisteae, Viciae, Loteae, and Trifoliae, were able to endure the severe climatic conditions, surviving and multiplying under extreme pressure (summer drought, winter frost). The Fabaceae family of flowering plants, which includes roughly 19,500 species divided into 751 genera, is regarded as the third largest flowering plant family. This enormous family has demonstrated a high degree of species diversity and evolutionary success in a variety of global ecosystems, including stony grasslands, deserts, seashores, alpine and arctic meadows (Choi and Ohashi 2003, Legume Phylogeny Working Group 2023). The Mediterranean and Irano-Turanic phytogeographical regions have some specific genera such as Onobrychis, Hedysarum, Medicago, Astragalus, Anthyllis, Trigonella, Coronilla, Hippocrepis, Ononis, Genista, etc. (Lesins and Lesins 1979, Polhill 1981). Two areas are distinctly bipolar for this speciation: the eastern Mediterranean and Irano- Turanic zone (around the Aegean, Black, and Caspian seas), and the western Mediterranean or lbero-Maghrebi (around the Tyrrhenian and Alboran seas). Within the genus Hedysarum, circum-Mediterranean, mostly eastern Medi- terranean, species are outstanding (among the 21 taxa recognized for Europe by Chrtková-Zertova, 1968, 13 are eastern Mediterranean). Among the 45 taxa recognized for the circum-Mediterranean areas by Greuter et al. (1989), 33 are present in the eastern Mediterranean. Corresponding author e-mail: burcuyilmaz@selcuk.edu.tr mailto:burcuyilmaz@selcuk.edu.tr POLLEN CHARACTERISTICS OF MULTICAULIA SECTION OF THE GENUS HEDYSARUM ACTA BOT. CROAT. 83 (2), 2024 101 In Türkiye alone, 22 taxa (one of which is suspect) of Hedysarum were recognized by Hedge (1979), and with the addition of the new taxa, the number of taxa in the genus will reach 24 (Bașköse et al. 2018, Aytaç et al. 2020, Hamzaoğlu and Koç 2020, Kandemir et al. 2023). Hedge (1979) separated Hedysarum into five sections (Hedysarum, Obscura, Multicaulia, Subacaulia, and Crinifera) in the Flo- ra of Türkiye. Of these, 11 are endemic to Türkiye, and the endemism ratio of the genus is 52.3%. The classification of sections of Hedysarum is also quite problematic. Until recently, it has included four sections: Hedysarum, Membranacea B. Fedtsch., Stracheya (Benth.) B.H. Choi & H. Ohashi, and Multicaulia (Boiss.) B. Fedtsch. However, section Multicaulia consists of three subsections: Multicaulia B.H. Choi & H. Ohashi, Crinifera (Boiss.) B.H. Choi & H. Ohashi, and Subacaulia (Boiss.) B.H. Choi & H. Ohashi. Characters such as the size, shape, and number of leaf- lets, indumentum, flower color, size, shape, and proportions of the standard, wings and keel, and shape and indumen- tum of the lomentum are extremely variable among the species of the Hedysarum genus (Hedge 1979). Hedysarum varium is the most common and polymorphic species of the genus in Türkiye. Hedge (1979) also noted that H. varium may be extended by hybridization or introgression with H. pestalozzae, H. syriacum, and H. nitidum. The differences between these four species are unsatisfactory, and further work is needed before their interrelationships and taxono- my can be placed on sounder foundations. The palynomorphology of the many Fabaceae taxa has taxonomic significance (Erdtman 1969, Ohashi 1971, Per- veen and Qaiser 1998, Pavlova and Manova 2000, Pınar et al. 2000, Avcı et al. 2013, Çeter et al. 2013, Bagheri et al. 2019). Three apertures, reticulate or suprareticulate orna- mentation of exine, oblate-spheroidal or prolate pollen grains were given in those studies. Additionally, the micro- morphological (pollen, fruit, and seed) characteristics can contribute to the discrimination of Hedysarum species, es- pecially the pollen grains and muri size. However, there has been no taxonomical study conducted on the pollen struc- tures of the subsection Multicaulia in Türkiye (Ohashi 1971, Polhill 1981, Faegri et al. 1989, Moore et al. 1991, Choi and Ohashi 1996, Civelek et al. 1999, Pavlova and Manova 2000, Sa et al. 2010, Ghanavati and Amirabadizadeh 2012, Dural and Citak 2015). In order to enhance the pollen morphological research into the genus Hedysarum, the current study was conducted to describe and evaluate in detail, for the first time, the palynomorphological properties of seven taxa distributed in Türkiye using light microscopy (LM) and scanning electron microscopy (SEM). The objectives of this work were to: 1) identify and investigate the features of the pollen grains of species belonging to the Multicaulia subsection; and 2) use numerical analyses to clarify the systematic significance of the palynological traits. Materials and methods Plant material The specimens of the section Multicaulia were collected from various localities, as listed in Table 1, and stored in the herbarium of the Department of Biology of Selçuk Univer- sity (KNYA). The taxonomical description of the species followed that of Hedge (1979). Palynological analysis Both LM and SEM were used to examine pollen grains of the genus Hedysarum. For palynological analysis, pollen samples of specimens were obtained from herbarium mate- rials. To observe and calculate the characteristics of pollen grains, the Wodehouse technique was used (Wodehouse 1935). In this unique and easy technique, pollen grains were separated from the anthers and were stained with glycerin- jelly and covered with coverslips. A Leica DM 1000 light microscope with a Canon 450D camera (Ota City, Tokyo, Japan) and software from the Kameram 21 program ( Argenit, Istanbul, Türkiye) was used to measure and observe fifty pollen grains per specimen. The equatorial diameter (E), polar axis (P), colpus length (Clg), colpus width (Clt), apocolpium (t), thickness of the exine and intine, and lumina width (LW) were examined and the P/E ratios were calculated. The mean, standard deviation (SD), minimum–maximum range, and mean values of these pollen characteristics for the taxa under study were given. The unacetolyzed pollen grains were transferred direct- ly onto aluminum stubs, covered with gold using a Cress- ington Auto 108 sputter coater (Cressington Scientific In- struments, Watford, Hertfordshire, UK) and photographed Tab. 1. Localities of specimens of Hedysarum from the section Multicaulia collected from various localities in Türkiye and stored in KNYA herbarium. Taxa Locality Herbarium no H. laxum (DC.) Spreng C5 Adana: Tufanbeyli, 1300 m. B. Çıtak-366 H. leucocladum Boiss. B5 Nevşehir: Zelve, 1100 m. B. Çıtak-150 H. huetii Boiss. A8 Erzurum: Tortum, 1300 m. B. Çıtak-377 H. nitidum Willd. A8 Erzincan: Refahiye, 1500 m. B. Çıtak-369 H. pestalozzae Boiss. C4 Karaman: Ayrancı, 1300 m. B. Çıtak-160 H. varium Willd. subsp. varium C4 Konya: Konya-Beyşehir road, 1300 m. B. Çıtak-161 B6 Sivas: Sivas-Erzincan road, 1500 m. B. Çıtak-367 H. varium subsp. syriacum (Boiss.) C.C. Towns. B5 Aksaray: Aksaray-Nevşehir road, 1150 m. B. Çıtak-151 ÇITAK B. Y. 102 ACTA BOT. CROAT. 83 (2), 2024 using a Zeiss Evo Ls10 scanning electron microscope (SEM) (Carl Zeiss NTS GmbH, Oberkochen, Germany) for the SEM analyses (Dural and Citak 2015). The pollen terminologies of Punt et al. (2007), and Halbritter et al. (2018) were followed. Statistical analysis The determined qualitative and quantitative characters were scored for numerical analysis. Nine pollen characters were used to evaluate Hedysarum taxonomic relationships. These characters are equatorial and polar axes, exine, in- tine, colpus length, colpus width, apocolpium, sculpture and lumen width. Next, the determined qualitative and quantitative characters were turned into a data matrix. For the pollen characters of the seven taxa, the coefficients of correlation were detected and compiled using the clustering analysis method (unweighted pair group method with arithmetic mean (UPGMA), dissimilarity, standardized variables). Using nine characters and seven taxa, a primary matrix was established for the multivariate analysis. The Gower general coefficient similarity (Gower 1971), which can be utilized directly to a variety of character types ( binary, qualitative, and quantitative characters), provided a basis for the clustering analysis. The UPGMA method was selected due to its widespread usage, congruence with the classification derived by traditional techniques, and visible accuracy in generating a reflection similarity matrix, as demonstrated by the co-phenetic correlation coefficient of Sokal and Rohlf (1962) and symmetrical hierarchical struc- ture (Sokal and Rohlf 1962, McNeill 1979). The covariance matrix was created using non-standardized, untrans- formed, and centered data (Citak 2019). All calculations were performed via MVSP 3.22 software (Kovach Comput- ing Services, Anglesey, Wales, Kovach 2013). Results Pollen morphology The pollen grains of the taxa of the subsection Multicaulia were determined as monad, radially symmetrical and iso- polar. The shapes of the pollen grains were elliptic and not compressed at the poles in equatorial view or orbicular in polar view (Fig. 1, Fig. 2). Quantitative characteristics of pollen grains from the plant samples are summarized in Table 2. The general pollen shape in this study was determined as prolate; subprolate pollen shape was observed only in H. nitidum. The highest average pollen grain diameter on polar axis was observed in H. laxum (22.85 µm), whereas the lowest diameter was observed in H. huetii (20.53 µm). Similarly, the maximum pollen grain diameter on the equa- torial axis was observed in H. nitidum (16.23 µm), while the minimum diameter was examined in H. laxum (12.68 µm). The size of the pollen grains was calculated based on the P/E ratio. The highest P/E value was observed in H. laxum (1.80), while the lowest value was observed in H. nitidum (1.33). Fig. 1. Pollen microphotographs of species of the Hedysarum genus of Multicaulia: a-d. H. laxum, e-h. H. leucocladum, ı-l. H. huetii, m-p. H. nitidum. Scale bar: 10 μm. POLLEN CHARACTERISTICS OF MULTICAULIA SECTION OF THE GENUS HEDYSARUM ACTA BOT. CROAT. 83 (2), 2024 103 All of the studied members of the subsection Multicaulia had tricolpate apertures. The investigated species had dif- ferent aperture sizes, with the maximum average colpi length observed in H. pestalozzae (19.84 µm), while the minimum was found in H. huetii (16.83 µm). In terms of the width, the maximum colpus width was found in H. nitidum (3.93 µm), while the minimum width was observed had microreticulate-perforate exine sculpturing, except for H. varium subsp. varium, which had reticulate-perforate exine sculpturing (Fig. 3). The exine thickness ranged from a maximum of 1.38 µm in H. nitidum to a minimum of 0.96 µm in H. varium subsp. varium. The lumina width also varied among the species, and ranged from a maximum of 1.10 µm in H. varium subsp. varium to a minimum of Fig. 2. Pollen microphotographs of species of Hedysarum genus of Multicaulia a-d. H. pestalozzae, e-h. H. varium subsp. varium ı-l. H. varium subsp. syriacum. Scale bar: 10 μm. Tab. 2. The palynomorphological characters examined in Multicaulia subsection (values in µm, except for P/E). PS: pollen shape, P: prolate, SP: subprolate, E: exine, I: intine, Clg: colpus length, Clt: colpus width, t: apocolpium, Sc: sculpturing, MP: microreticulate- perforate, RP: reticulate-perforate, LW: lumina width. Fifty pollen grains per specimen were analyzed. * indicates endemic taxa and **indicates characters used in statistical analysis. Taxa Equatorial axes (E)** Polar axes (P)** P/E PS E** I** Clg** Clt** T** Sc** LW** Min – Max Mean ± SD Min – Max Mean ± SD *H. laxum 10.28 – 15.34 12.68 ± 1.81 17.67 – 25.26 22.85 ± 2.37 1.80 P 1.3 0.58 19.23 3.14 3.10 MP 0.57 H. leucocladum 13.26 – 15.76 14.31 ± 0.78 19 – 22.38 21.03 ± 1.09 1.46 P 1.27 0.62 19.55 2.97 2.97 MP 0.53 H. huetii 13.55 – 15.28 14.7 ± 0.7 19.2 – 21.78 20.53 ± 1.09 1.39 P 1.06 0.54 16.83 2.99 4.39 MP 0.59 *H. nitidum 15.64 – 16.91 16.23 ± 0.47 19.65 – 23.77 21.67 ± 1.13 1.33 SP 1.38 0.63 19.71 3.93 3.25 MP 0.74 *H. pestalozzae 9.8 – 16.24 13.6 ± 2.04 16.37 – 22.65 20.96 ± 1.54 1.54 P 1.00 0.74 19.84 3.45 3.19 MP 0.50 H. varium subsp. varium 10.41 – 18.13 15.76 ± 2.44 19.64 – 23.79 21.57 ± 1.13 1.36 P 0.96 0.66 19.69 3.6 2.74 RP 1.10 H. varium subsp. syriacum 14 – 15.44 14.76 ± 0.44 21.03 – 23.67 22.34 ± 0.88 1.51 P 1.16 0.55 19.17 3.82 3.61 MP 0.62 in H. leucocladum (2.97 µm). An operculum with psilate ornamentation on the colpus was determined in all pollen grains. The exine ornamentation was the most distinguishing character of the species. In current study, all of the species 0.50 µm in H. pestalozzae. The sculpture of pollen grains was microreticulate-perforate or reticulate-perforate in equatorial view; however, only perforate ornamentation was observed in polar view. The walls of the muri were sinuous in the examined species. ÇITAK B. Y. 104 ACTA BOT. CROAT. 83 (2), 2024 Numerical analysis of the pollen characters traits A dendrogram produced with the use of the UPGMA in the cluster analysis, taking into account the ten palynolog- ical variables (Tab. 2) found in the section Multicaulia, is shown in Fig. 4. Similarities among the investigated taxa were reflected in the dendrogram, which revealed two main groups: group A (with 45% similarity) contained only H. huetii, which was a distinct species, and group B (with 60% similarity) comprised the remaining 6 taxa. Group B comprised two primary clusters, further denoted as clusters C and D. Two species (H. pestalozzae and H. varium subsp. varium, with a 73% similarity) made up cluster C. Four taxa with two subgroups, clusters D1 and D2, were included in cluster D. Cluster D1 contained H. laxum and H. leucocladum. Cluster D2 also included 2 species: H. nitidum and H. varium subsp. syriacum. Discussion The present study examined the usefulness of using the pollen morphological characteristics of species of the sec- tion Multicaulia of the genus Hedysarum in Türkiye. Using Fig. 3. Electron microphotographs of species of Hedysarum genus of Multicaulia. a-b. H. laxum, c-d. H. leucocladum, e-f. H. huetii, g-h. H. nitidum, ı-j. H. pestalozzae, k-l. H. varium subsp. varium, m-n. H. varium subsp. syriacum. Scale bar (a, c, e, g, ı, k, m): 2 µm; scale bar (b, d, f, h, j, l, n): 1 µm. Fig 4. The derived dendrogram based on the palynological characters showing the similarity distance of Hedysarum species. POLLEN CHARACTERISTICS OF MULTICAULIA SECTION OF THE GENUS HEDYSARUM ACTA BOT. CROAT. 83 (2), 2024 105 these pollen morphological characters, delimitation of taxa was determined. The findings of current investigation show that the pol- len dimensions (E and P/E ratio), the thickness of the exine and intine, the shape of the polar and equatorial views, and the aperture type of the Türkiyeli representatives of Hedysarum were comparatively homogeneous (Tab. 2, Fig. 1). Ohashi (1971), Ferguson and Skvarla (1981), Faegri and Iversen (1989), Moore et al. (1991), Pavlova and Manova (2000), and Ghanavati and Amirabadizadeh (2012) con- firmed that the pollen morphological characteristics of the different sections of Hedysarum are essentially the same. Polar and equatorial axes were useful pollen characters to group species with the aid of numerical analysis as men- tioned before in Astragalus (Bagheri et al. 2019). Another study declared that Onobrychis genus had oblate-spheroidal pollen shape (Avcı et al. 2013). All of the species investigated in this research had tri- colpate-type pollen grains with microreticulate-perforate exine ornamentation. Only H. varium subsp. varium was different from others, with reticulate-perforate exine. Reticulate and finely reticulate exine ornamentation were reported previously in the genus Hedysarum by Civelek et al. (1999), Pavlova and Manova (2000), and Dural and Citak (2015). The sculpture of exines were determined with three types counted reticulate, suprareticulate and microreticu- late in close relatives of Hedysarum genus, Astragalus and Onobrychis (Avcı et al. 2013, Bagheri et al. 2019). Perveen and Qaiser (1998) reported that the ornamentation, and in particular, the shape and size of the muri and lumina, was an important character for Fabaceae (Pavlova and Manova 2000, Ghanavati and Amirabadizadeh 2012, Dural and Citak 2015). The colpus membrane has been identified as being covered with large and small sculptural elements by different researchers in the genus Hedysarum (Pavlova and Manova 2000, Dural and Citak, 2015). Moreover, in this study the same sculptural elements were observed in the subsection Multicaulia as described for the operculum with psilate sculpture. The UPGMA dendrogram derived based on the paly- nological characters discriminated the species of the sub- section Multicaulia. The positions of the species and the re- lationships of the subsection Multicaulia of the genus Hedysarum in the cluster were found to be in agreement with the previous classification made on a large scale (Hedge 1979, Hamzaoğlu and Koç 2020). H. huetii, which is a very distinct species, can be easily separated from the others by its fleshy and ovate-orbicular leaflets; hence, it was alone in a different subclade. It was very surprising that H. pestalozzae and H. varium subsp. varium were in the same clade, because of their broad morphological differences, particu- larly regarding the color of the corolla. In addition, the po- sitions of H. varium subsp. syriacum and H. nitidum in the same clade were surprising due to their morphological dif- ferences. This situation raised the question of whether or not new taxonomic regulations for these taxa are required. The last two species, H. laxum and H. leucocladum, which are local and endemic, were in the same subclade. The dis- tribution of the species of the subsection Multicaulia has raised the question of whether or not the relationships of the taxa should be reviewed one more time based on their pollen characteristics. Furthermore, different lumina di- mensions, lumina types, and densities among taxa may be associated to their multiple germination requirements or dispersal strategies, which may have developed as a result of an evolutionary adaptation independent of various habi- tat types or microclimatic regions, particularly for endem- ics. More data are needed to solve the systematic problems of this section, especially regarding the phylogenetical rela- tionships of the taxa. Conclusion To sum up, an in-depth investigation of the pollen char- acters was highly helpful in classifying the studied taxa. In future work, we propose that the systematic problems still unresolved in Hedysarum taxa should perhaps be solved by combining morphological with anatomical, micromorpho- logical, karyological, and additional molecular data. Acknowledgments The author thanks Dr. Hüseyin Dural for helping to identify the plant samples of the species of H. pestalozzae and H. varium. References Avcı, S., Sancak, C., Can, A., Acar, A., Pınar, N. M., 2013: Pollen morphology of the genus Onobrychis (Fabaceae) in Turkey. Turkish Journal of Botany 37(4), 669–681. https:// 10.3906/ bot-1207-52 Aytaç, Z., İğci, B. K., Körüklü, T. S., 2020: Hedysarum nallihanse (Fabaceae): A new species from Turkey. Phytotaxa 471(3), 276–282. https://doi.org/10.11646/phytotaxa.471.3.9 Bagheri, A., Roofigar, A. A., Abbasi, S., Maassoumi, A. A., Rut- ten, T., Blatner, F. R., 2019: Pollen morphology of Astragalus section Hymenostegis (Fabaceae) and evaluation of its sys- tematic implications. Grana 58(5), 328–336. https://doi.org/1 0.1080/00173134.2019.1621931 Bașköse, İ., Yaprak, A. E., Akyıldırım, B., 2018: Hedysarum ke- tenoglui (Fabaceae-Hedysareae), a new species from southern Turkey. Phytotaxa 357(4), 291–297. https://doi.org/10.11646/ phytotaxa.357.4.5 Çeter, T., Erkul, S. K., Aytaç, Z., Başer, B., 2013: Pollen morphol- ogy of the genus Oxytropis Dc. in Turkey. Bangladesh Journal of Botany 42(1), 167–174. https://doi.org/10.3329/bjb. v42i1.15908 Choi, B., Ohashi, H., 1996: Pollen morphology and taxonomy of Hedysarum and its related genera of the tribe Hedysareae (Le- guminosae: Papilionoideae). Journal of Japanese Botany 71, 191–213. Choi, B., Ohashi, H., 2003: Generic criteria and an ifrageneric system for Hedysarum and related genera (Papilionoideae- Leguminosae). Taxon 52, 567–576. Citak, B. Y., 2019: A palynological survey of the genus Iberis (Brassicaceae), known as candytufts, in Turkey. Phytotaxa 397, 213–224. ÇITAK B. Y. 106 ACTA BOT. CROAT. 83 (2), 2024 Civelek, S., Yaman, A., Sahin, A., Gur, N., 1999: The investigation in point of chromosome number, morphological, anatomical and pollen characteristics of Hedysarum aucheri Boiss. Jour- nal of Science and Engineering of Fırat University 11, 77–88. Dural, H., Citak, B. Y., 2015: Morphology and anatomy of Hedys- arum pannosum (Boiss.) Boiss.(Fabaceae). Acta Botanica Croatica 74(1), 19–29. https://doi.org/10.1515/bot- cro-2015-0009 Erdtman, G., 1969: Pollen Morphology and Plant Taxonomy. New York, Hafner Publishing. Faegri, K., Iversen, J., 1989: Textbook of pollen analysis. John Wi- ley & Sons, Chichester. Ferguson, J. K., Skvarla, J. J., 1981: The pollen morphology of the subfamily Papilionoideae (Leguminosae). In: Polhill, R.M., Raven, P.H. (eds.), Advances in Legume Systematics. 859– 896. Kew Royal Botanic Gardens, London. Ghanavati, F., Amirabadizadeh, H., 2012: Pollen grain morphol- ogy in Iranian Hedysareae (Fabaceae). Crop Breeding Journal 2(1), 25–33. http://dx.doi.org/10.22092/cbj.2012.100413 Gower, J. C., 1971: A general coefficient of similarity and some of its properties. Biometrics 27, 857–871. https://doi. org/10.2307/2528823 Greuter, W., Burdet, H. M., Long, G., 1989: Med-Checklist. A critical inventory of vascular plants of the circum Mediter- ranean countries. 4. – Genève: Conservatoire et Jardin bota- niques de la Ville de Genève; Berlin:Secrétariat Med-Check- list, Botanischer Garten und Botanisches Museum Berlin-Dahlem. Halbritter, H., Ulrich, S., Grimsson, F., Weber, M., Zetter, R., Hes- se, M., Buchner, R., Svojtka, M., Frosch-Radivo, A., 2018: Il- lustrated pollen terminology. Second edition. Springer. Hamzaoğlu, E., Koç, M., 2020: Hedysarum turcicum (Hedysare- ae, Fabaceae), a new species from Turkey. Phytotaxa 428(1), 1–6. https://doi.org/10.11646/phytotaxa.428.1.1 Hedge, I. C., 1979: Hedysarum L. In: Davis, P. (ed.), Flora of Tur- key and the East Aegean Islands. 560–589. Edinburgh Uni- versity Press, Edinburgh. Kandemir, A., Sevindik, E., Yıldız, F.,Türkoğlu, H. İ.,Yıldız, B., 2023: A new species of Hedysarum (Fabaceae) from Turkey. Phytotaxa 587(1), 12–20. https://doi.org/10.11646/phyto- taxa.587.1.2 Kovach, W. L., 2013: MVSP – A MultiVariate Statistical Package, MVSP Version 3.22, Kovach Computing Services, Pentraeth, Wales, U.K. http://www.kovcomp.co.uk/downl2.html Legume Phylogeney Working Group, 2013: Legume phylogeny and classification in the 21st century: progress, prospects and lessons for other species-rich clades. Taxon 62(2), 217–248. https://doi.org/10.12705/622.8 Lesins, K. A., Lesins, I., 1979: Genus Medicago (Leguminosae): a taxogenetic study. Dr. W Junk bv Publishers, Boston. McNeill, J. 1979: Structural value: a concept used in the construc- tion of taxonomic classifications. Taxon 28, 481–504. https:// doi.org/10.2307/1219786 Moore, P. D., Webb, J. A., Collison, M. E., 1991: Pollen analysis. Blackwell scientific publications, Oxford. Ohashi, H., 1971: A taxonomic study of the tribe Coronilleae (Le- guminosae), with a special reference to pollen morphology. Journal of the Faculty of Science, University of Tokyo, Section III Botany 3, 25–92. Pavlova, D. K., Manova, V. I., 2000: Pollen morphology of the genera Onobrychis and Hedysarum (Hedysareae, Fabaceae) in Bulgaria. Annales Botanici Fennici 37(3), 207–217. http:// www.jstor.org/stable/23726902 Perveen, A., Qaiser, M., 1998: Pollen flora of Pakistan - X. Legu- minosae (subfamily: Caesalpinioideae). Turkish Journal of Botany 22(3), 145–150. Pınar, N. M., Vural, C. Aytaç, Z., 2000: Pollen morphology of Ebenus L. (Leguminosae: subfamily Papilinoideae) in Turkey. Pakistan Journal of Botany 32(2), 303–310. Polhill, R. M., 1981: Evolution and systematics of the Legumino- sae. Advences in Legume Systematics 1, 1–26. Punt, W., Hoen, P. P., Blackmore, S., Nilsson, S., Le Thomas, A., 2007: Glossary of pollen and spore terminology. Review of Palaeobotany and Palynology 143(1–2), 1–81. https://doi. org/10.1016/j.revpalbo.2006.06.008 Sa, R., Su, D., Debreczy, Z., 2010: Taxonomic notes on the Hedys- arum gmelinii complex (Fabaceae). Annales Botanici Fennici 47(1), 51–58. http://www.jstor.org/stable/23728274 Sokal, R.R., Rohlf, F.J., 1962: The comparison of dendrograms by objective methods. Taxon 11, 33–40. http://dx.doi. org/10.2307/1217208. Wodehouse, R. P., 1935: Pollen grains. Mcgraw-Hill Book Com- pany, New York, London.